1. Field of the Invention
The present invention relates to a revolving door which has at least one night closing panel or security panel, which panel runs concentric to at least one barrel-type wall. The panel slides or rolls on a guide rail which is located on the ceiling structure or on attachments to the ceiling structure, and the night closing panels can be moved with respect to the barrel-type wall by at least one flexible, endless tension means.
2. Background Information
British Patent Application 2 052 612 A describes a motor-driven closing device, by means of which the inner exit from a revolving door can be blocked, to prevent the entry of armed persons into the interior of a building. The closing device is driven by a motor which is located on the frame of the revolving door. The motor drives a circulating chain which, for its part, is coupled to a movable wall segment that runs centrally. Only one wall segment can be coupled to the circulating chain, i.e. the connection of two night closing panels that move in opposite directions is not possible. Moreover, in addition to the chain, a plurality of deflection pulleys are required, which makes the whole system more complex and expensive to construct and reduces its efficiency.
German Patent No. 39 28 911 C2 discloses an additional opening/closing mechanism for curved sliding doors which uses an endless belt with two horizontal strands which lie next to one another. The endless belt is thereby looped around the drive belt pulley and the driven belt pulley, whereby simultaneously the two door panels are firmly connected to the endless belt. When the drive motor is energized, the two door panels are actuated so that they move in opposite directions along left and right guide rails respectively. This type of drive mechanism is complex and expensive, because it requires a plurality of guide rollers and deflector pulleys. When toothed belts are used as the endless belt, it is also necessary to twist the toothed belts by 180.degree. so that they can be guided on the corresponding guide rollers. The efficiency of the drive mechanism is further reduced by the friction resistances of the guide rails and rollers.